Certain mobile platforms, such as aircraft, are commonly equipped with Cabin Pressure Control Systems (CPCSs), which maintain cabin air pressure within a desired range to increase passenger comfort during flight. A representative CPCS may include an outflow valve. The outflow valve is fluidly coupled between the aircraft's cabin and an ambient pressure external to the aircraft (referred to herein as “ambient”). During operation of the CPCS, the outflow valve is moved between various positions to control the rate at which pressurized air from the aircraft's cabin is vented to ambient. By moving the outflow valve between the various positions, the CPCS may maintain the aircraft's cabin pressure within a desired range. Furthermore, the outflow valve may be positioned such that the pressurized air exhausted by the outflow valve provides additional forward thrust to the aircraft.
However, by fluidly coupling the outflow valve to the aircraft cabin and the ambient pressure external to the aircraft, the operation of the outflow valve may generate undesirable noise in the aircraft cabin. In one example, the flow of air through the outflow valve during climb or descent of the aircraft may result in tonal noise within the aircraft cabin, which is undesirable. In order to mitigate the tonal noise, certain outflow valves include one or more vortex generators. In certain instances, however, these vortex generators may create broadband noise during cruise operation of the aircraft, which is also undesirable to occupants in the aircraft cabin.
Accordingly, it is desirable to provide an improved outflow valve, which reduces both tonal noise and broadband noise within the aircraft cabin, while maintaining cabin air pressure and providing additional forward thrust to the aircraft. Furthermore, other desirable features and characteristics of the present invention will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.